1	INDOOR AIR QUALITY John A. Schaefer CIH, HEM, CPEA Associate Director HSE Assistant Professor of Medicine Assistant Professor of Environmental Health Sciences
2	DEFINITIONS Indoor Air Quality Overall quality of the indoor air includes physical, chemical and biological factors HVAC System Equipment and distribution system used for heating, distributing cooling, and filtering air for a building for the purpose of the comfort and health of the occupants
3	DEFINITIONS Outdoor air Air from outside the building used to replace all or part of the air in a building Supply air Conditioned air delivered to the occupied space Return air Air that has been in the building for a period of time and returned to the ventilation system. Varying amounts of return air is exhausted or redistributed
4	DEFINITIONS Fan Device to move air through the HVAC system Air cleaners Devices to remove impurities from air includes filter, scrubbers, and electrostatic precipitators Control zone A space in a building served by the HVAC system
5	HVAC SYSTEM TYPES Constant Supplies a constant volume of ventilation to the control zone Variable Supplies variable amount of ventilation to the control zone depending on the occupants needs Demand Supplies ventilation to the control zone only when heating or cooling is needed
6	HVAC SYSTEM TYPES Single pass All ventilation is exhausted out of the building and replaced with outside air Re-circulated A percentage of the ventilation is exhausted from the building and replaced with outside air. This is an energy saving practice The amount of re-circulation is based upon the temperature of the outside air
7	ACRONYMS ASHREA – American Society of Heating Refrigeration and Airconditioning Engineers – Recommendations on acceptable ventilation for comfort ACGIH - American Conference of Governmental Industrial Hygienist Recommendations on ventilation design and acceptable levels of exposure to hazardous substances for workers.
8	ACRONYMS EPA – Environmental Protection Agency Published “Building Air Quality” OSHA – Occupational Safety & Health Agency – Regulates worker exposure – No IAQ standard MOSH – Maryland Occupations Safety & Health – Maryland’s OSHA – No IAQ standard - exposure to tobacco smoke standard
9	Ventilation for acceptable IAQ: ASHRAE Temperature Winter (heating season) 67-79^o F Summer (cooling season) 72-81^oF Humidity Winter (heating season) 20 –30 % relative humidity Summer (cooling season) <60 % relative humidity Carbon dioxide <1000 ppm OZONE <0.05 ppm
10	Ventilation for acceptable IAQASHRAE Outside air recommendations for educational facilities AREA CFM/person* Classroom 15 Office 20 Laboratory 20 Library 15 Auditorium 15 * cubic foot per minute of outside air per person occupying the area as designed
11	IAQ MANAGEMENT PROGRAM Controlling the Air Quality in an building is a complex multi-faceted function requiring the commitment of: Administration Management/Supervisor Environmental Health and Safety Worker’s Compensation/medical management Facilities/Building Owner Employees
12	IAQ MANAGEMENT PROGRAM ADMINISTRATION Commit to properly designed ventilation systems Commit to routine preventative maintenance Commit staff to properly investigate and correct problems found Be willing to allow for unbiased medical evaluation of those who have concerns
13	IAQ MANAGEMENT PROGRAM MANAGEMENT/SUPERVISOR Accept the concerns of staff Request evaluation of the work area Refer staff for medical evaluation Accept the results of the evaluation Put into action recommendations of the evaluation No reprisals on staff that expressed concerns
14	IAQ MANAGEMENT PROGRAM ENVIRONMENTAL HEALTH & SAFETY Accept concerns are real Evaluate the concerns without biases Evaluate the concerns completely Document the findings of the evaluation Generate a complete report of findings and recommendations Follow up to ensure that the recommendations are implemented
15	IAQ MANAGEMENT PROGRAM WORKERS COMPENSATION/ MEDICAL MANAGEMENT Evaluate concerned staff to determine if staff has medically valid concerns Refer to specialists as necessary Evaluate medical findings in conjunction with EH&S evaluation results Recommend treatment and accommodations as dictated by medical and EHS results
16	IAQ MANAGEMENT PROGRAM FACILITIES/ BUILDING OWNER Maintain operation of building HVAC system Assist EHS in their evaluation Put into place recommendations from EHS Report to EHS modifications to the systems Report to EHS any activities that could generate odors Report to EHS any failures of the HVAC system
17	IAQ MANAGEMENT PROGRAM EMPLOYEES/FACULTY/STUDENTS/PARENTS Willing to report only those concerns which they feel are valid Willing to accept the evaluation of medical and EHS staff Willing to make adjustments that are recommended Willing to eliminate odor producing material from the work area
18	IAQ MANAGEMENT PROGRAM PRATICAL ASPECTS Document the design and maintenance of the ventilation systems Document the filtration efficiency of the systems Modify filtration if increased filter efficiency is needed Update information on a periodic basis.
19	IAQ MANAGEMENT PROGRAM PRACTICAL ASPECTS Medical Evaluation In conjunction with worksite evaluation Worksite Evaluation Conducted without medical information so as not to direct evaluation
20	IAQ MANAGEMENT PROGRAM MEDICAL EVALUATION Document symptoms Identify underlying medical conditions Allergy testing Specialist referrals Eliminate sources of symptoms Conclusions as to the causal relationship of the symptoms to the workplace
21	IAQ MANAGEMENT PROGRAM WORKSITE EVALUATION Document condition of the ventilation system Documents conditions within the workplace CO2, Temperature, Humidity, dust mite, cockroach, mold in carpet and mold in the air. Document point sources of releases. Recommend corrective actions
22	IAQ INVESTIGATION SAMPLING Conducting random sampling with no forethought will not provide any useable information at best and may provide erroneous information at the worst. Based upon the information developed on the HVAC system and maintenance schedule a protocol should be developed to determine the proper procedures to follow
23	IAQ INVESTIGATION Initial steps include identifying specific location of complaints General area Isolated to a specific area Interview occupants to identify the characteristics of the complaint Identify if complaints are periodic, or constant, or associated with specific activities
24	IAQ INVESTIGATION Is the system operating as designed Evaluate air intakes Location - close to contamination sources? Is the intake free of debris and mold Are filters intact and changed frequently Evaluate heating and cooling coils Are they free of contamination/ mold Evaluate drip pans Are they clean and free of mold and standing water Evaluate outside dampers Are they working properly Are they set properly
25	IAQ INVESTIGATION HVAC SYSTEM Are there sources of contaminants that can enter the HVAC system from within and outside the system Identify sources Identify control mechanism Identify corrective actions Implement control and corrective actions
26	IAQ INVESTIGATION HVAC SYSTEM Ventilation Is the amount of ventilation adequate Air flow into the room – measure air flow through the supply and exhaust diffusers – compare to design specifications. Calculate the amount of outside based upon the outside damper setting to determine percentage of air flow which is outside air
27	Monitoring for Acceptable IAQ Temperature/ Humidity Psychrometer – gives only the measurement at time taken Thermal hydrograph – evaluate the HVAC system temperature control over a period of time (7days) Carbon Dioxide Detector tubes – measurement at time taken Infrared CO₂ monitor evaluate HVAC system CO₂ control over a period of time (7 days)
28	IAQ INVESTIGATION CONTAMINATION Chemicals (only when indicated by investigation) If specific chemical can be identified monitoring for the specific chemical can be conducted If no specific chemical is identified then a screen for 25 common volatile chemicals is initiated
29	IAQ INVESTIGATION CONTAMINATION Biological If indicated a vacuum sample to determine if allergens are present in carpeted areas Mold Cockroach Dust mites
30	IAQ INVESTIGATION CONTAMINATION Allergen sample results (risk factors) Mold (colonies/gram dust) Low risk <10,000 Moderate risk 10,000 – 25,000 High risk >25,000 Cockroach Any positive results
31	IAQ INVESTIGATION CONTAMINATION Allergen sample results (risk factor) Dust mites (ng allergen/gram dust) Detection limit 20 Low risk for symptoms <400 Moderate risk of symptoms 400 – 2,000 High risk for symptoms 2,000- 10,000 High risk for sensitization >10,000
32	IAQ INVESTIGATION CONTAMINATION Airborne mold (only conducted if indicated) Sampler Anderson single stage sampler Sample location Outside building by air intake Complaint area Areas adjacent Results Compare sample locations
33	ACHIEVING GOOD IAQ Good IAQ can be achieved by Properly designing systems to meet ASHRAE recommendations Properly maintained HVAC system Filter changes Routine preventative maintenance Eliminate or control sources of contamination from within the building Ensure outside contaminants do not enter the air intakes
34	ACHIEVING GOOD IAQ Protocols to evaluate contaminants from projects Listing of hazardous materials used in the project Evaluate MSDS of each substance Identify those substances which may cause respiratory problems Eliminate or control potential sources of substances of concern